Splitting machine for sheet material



Nov. 5, 1963 D. BRAUN ETAL SPLITTING MACHINE FOR SHEET MATERIAL 2 Sheets-Sheet 1 Filed Feb. 9, 1961 Y Mw@ gm Nov. 5, 1963 D. BRAUN ETAL 3,109,339

SPLITTING MACHINE FOR SHEET MATERIAL Filed Feb. 9. 1961 2 Sheets-Sheet 2 Tg2 W FIG.3

Tir-M4 kaf/L auf ilnited States harem@rg SPLlTTEJG MACHINE FR SIJEET MATERIAL Dieter Braun, Stuttgart-Bad annstatt, Ernst Focke, Stuttgart, and Kurt Hacker, tuttgart-Zutfenhausen, Germany, assignors to Formas-Werke Spezialnraschinenfabrik A.G., Stuttgart-Earl Cannstatt, Germany Filed Feb. g, 196i, Ser. No. SSJol Claims priority, application Germany Feb. l0, 196@ 2@ Claims. (Cl. SS-e) The present invention relates to a splitting machine for sheet material, and more particularly to a control arrangement for a splitting machine by which an irregular sheet material, such as animal skins, is split into two layers one of which is to be cut to a selected thickness.

Machines of this type are known in which the sheet material is compressed between a pair of transporting rollers and transported by the same `toward a cutting means, for example a moving cutter band located in the plane of the sheet material so as to cut the same into two layers.

In view of the fact that the hardness and compressibility of the sheet material varies to a great extent, the spacing of the transporting and compressing roller from the cutting edge of the cutter band does not fully determine the thickness of the split-off layer which is nally used. The diiferences of the properties of hard leather, soft suede, or even rubber sheets is so substantial that these materials expand `to a different extent lafter being released from the pressure between the transporting rollers and the cutter band.

Consequently, it has been necessary to measure and to assort the split sheets produced by the prior art machines, or to assort the sheet material according to hardness wd thickness so lthat the splitting machines could be supplied with workpieces having similar properties. Nevertheless, it has not been possible to obtain nished split pieces having a selected thickness within desirable tolerances.

If the produced split material is too `thick or too thin, the transporting rollers have -to be adjusted for the next workpiece. However, if the split workpiece is too thin, it must be discarded, while workpieces which turn out too thick can he run a second time through the machine. The amount of adjustment on the transporting rollers has to be estimated in the machines of the prior art, and even the adjusted transporting rollers may turn out material having an undesired thickness. It is customary -to determine the thinnest portion of each sheet material, and to adjust the transporting rollers to cut a layer corresponding to such thinnest portion, in which event split layers of diterent thickness are produced of diierent skins.

However, even if the transporting rollers are properly adjusted, a uniform thickness of the split layer is not assured, since the parts of a skin may be of different hardness, depending on whether the slain comes from the back, the side, or any other pant of the animal.

In View of these facts, split material produced by the` machines of the prior art, practically require measuring of each workpiece, causing loss of time, and unduly high labor costs.

It is one object of the present invention to improve the splitting machines of the prior art, and to provide a splitting machine for sheet material capable of producing a split layer of uniform thickness irrespective of the properties and thickness of the split sheet material.

Another object of the present invention is to provide a splitting machine for animal skins capable of splitting layers of uniform thickness from irregular skins Another object of the present invention is to provide a splitting machine with a control device including a 31,l0 9,3-39 Patented Nov. 5, 1963 ice feeler measuring the thickness of a split-off layer of the split sheet material.

Another object of the presen-t invention is to measure the sheet material between a feeler and a roller moving at the same peripheral speed as the sheet material, for example one of ythe transporting rollers.

Another object of the present invention is to transmit the feeler motion to control means controlling a motor by .which a transporting roller is pressed 4'against the transported sheet material and a counter-pressure roller for adjusting the position of the sheet material relative to the cutting means.

Another object of the present invention is to provide a control circuit for effecting adjustment of the machine in such a manner that a sheet having a thickness within a selected range of tolerances is produced.

With these objects in view the present invention relates to a splitting machine for splitting a sheet material, such as leather or rubber. One embodiment of the machine comprises cutting means, for example a moving cutter band; transporting means for transporting the sheet material toward the cutting means and for pressing the sheet material against the cutting means; and a control device including a feeler located behind the cutting means for sensing the thickness of a layer split ofi the sheet material by the cutting means. The control device is connected to the transporting means to adjust the same relative to the cutting means until the feeler senses a desired thickness of the split-oli layer. in this manner, a layer of the desired thickness can be obtained irrespective of the thickness, compressibility and actual compression of the sheet material.

In :the preferred embodiment of the invention, the transporting means include a driven pressure roller, and a resiliently supported counter-pressure roller. The rollers transport the material in one direction toward the cutting means, and the pressure roller is driven and movable toward and away from the counter-pressure roller and is adjusted by a motor in accordance with the position of the feeler.

A meter measures the displacement Iof the feeler, and operates a movable contact between two stationary contacts which are connected in the circuit of the motor to elect reversal of the motor when the movable Contact engages one of the two fixed contacts. In the intermediate position of the movable contact, the motor is not energized and the pressure roller is not adjusted, since a split layer having the desired thickness within the range of tolerances is being produced. Engagement of the movable contact with one of the stationary contacts indicates that the produced layer is either too thick or too lthin, and the motor eects the corresponding adjustment of the pressure roller until the feeler senses a split layer having the desired thickness.

The motor can also be operated by manually controlled switches to obtain a preliminary setting of the pressure roller according to la suitableindicator. The position of the meter relatvie Ito `the feeler can also be manually adjusted, and a scale is provided for indicating the position of the meter.

A control switch is operated by the resiliently supported counter-pressure roller to permit operation of the motor only when sheet material has been inserted into the transporting means. Preferably, delay means are provided in the circuit of the motor so that no adjustment takes place before the leading portion of the material has reached the feeler.

The novel features which are considered as characteristic for the invention are set forthv in particular in the appended claims. The invention itself, however, both as to its construction and its method of operation together with additional objects and advantages thereof, will be best understood from the following description of specic embodiments when read in Yconnection with the accompanying drawings, in which:

FIG. l is a fragmentary sectional View illustrating a preferred embodiment of the invention;

FlG. 2 is a longitudinal sectional view of a sheet material indicating the tolerances determining the maximum and minimum desirable thickness of the finished product; and

FG. 3 is a diagram illustrating the control circuit controlling the adjusting motor in accordance with the position of the feeler.

Referring now to the drawings, and more particularly to FIG. l, the frame l5 of the machine has a horizontal portion le in which spindle means E9 are mounted for axial movement, but non-turnable. The spindle 19 has a threaded portion with which a threaded inner bore of a worm gear 18 meshes so that turning of gear i3 eifects axial displacement of spindle 17 together with a support i4 on which a roller 2 is turnably mounted. Roller 2 is driven by a motor, not shown, mounted on support 14.

The worm gear le meshes with the worm screw 23 on a shaft 22 of a gear 2l which meshes with a gear Ztl on the shaft of a drive motor 13. ln accordance with the direction of rotation of motor i3, roller 2 wiil be either raised or lowered. A chain wheel Z4 is integral with the worm gear i8, and serves for connecting the drive motor i3 to another spindle, not shown, of a corresponding arrangement.

The counter-pressure roller 3 is located opposite pressure roller 2., and is turnably mounted on a supporting arm 26 which is pivotally supported by a shaft Z7. A projection 34 of supporting arm 26 is engaged by a shiftable member 33 which is mounted in a frame portion 32 of the machine. A spring 29 abuts the head 2S of shiftable member 33 and urges the same against projection 34 so that supporting arm 26 moves upwardly together with counter-pressure roller 3. A llange Btl of shiftable member 33 engages frame portion 32 in an end position of shiftable member 33 in which the peripheral surface of counter-pressure roller 3 is located in a working plane passing through a cutter band 5 having a cutting edge 4.

A work table 25 has an upper surface located slightly below the Working plane, and supports a workpiece ll for movement toward the gap between pressure roller 2 and counter pressure roller 3. When a workpiece 1 is located between rollers 2 and 3, roller 3 is displaced from its normal position, so that flange 3? moves away from frame portion 32 and engages the pin 31 of a control switch 7 to close control switch 7 which is open when no Workpiece 1 is located between the rollers.

A workpiece gripped by rollers 2 and 3 is compressed and has the thickness e instead of its natural thickness a. The workpiece is pressed against the cutting edge d and split into two layers which resiliently expand again to have the thicknesses c and d, respectively. The initial thickness a of a sheet material l is the sum of the thicknesses c and d. However, along the line S Where a plane passing through the axis of the pressure roller 2' and through the cutting edge 4 intersects with the peripheral surface of pressure roller 2, the upper layer is still compressed between roller 2 and the cutter band 5. Due to the variable properties of the used sheet material, the thickness c cannot be determined from the width of the gap e, or from the width of the gap b.

In the illustrated embodiment, the cutter band 5 is an endless loop slidably guided in a slot of a support, and having a cutting edge d moving in axial direction of the rollers 2 and 3. Only the upper split layer is used, and the lower split layer is discarded as waste. The upper layer is received by a conveyor means 41 and transported to a suitable place where it can be deposited.

A scale member 92 is secured to the frame 1S, and cooperates with a pointer Q3 on the movable support i4. The. scale 92 preferably indicates the thicknesses c of the usable split layer which is expected to be obtained in the respective position of the pressure roller 2. However, the scale 92 may also be designed to indicate the compressibility of the material.

Support 1,4 has an arm S9 on which a slide 86 is mounted for movement in the same direction in which the pressure roller 2 is adjusted by motor 13. A manually operated member is connected through a micrometer drive to a threaded spindle which meshes with a corresponding inner thread in slide Se to move slide 36 between terminal positions in which a fixed pin 5@ on slide 86 abuts two spaced stops 5l and S2 on supporting arm 89.

Slide Se has a projecting arm in which a meter 84 is mounted. T he sensing finger 87 of meter S4 is operatively connected to a pointer 6l which is also a movable Contact turning between two end positions determined by two iixed contacts il and 12..

The feeler means includes an angular lever S3, 83 which is turnably mounted on a pin 82 on a bracket 94 on supporting arm S9. A spring 5'5 abuts arm S6 and arm S8, and urges lever 33, St? to turn in clockwise direction so that a feeler roller 6 which is turnably mounted on lever arm 33, is urged against the upper split layer of a workpiece, and toward the pressure roller 2.

A pointer di? on slide 36 cooperates with a scale means d8 on supporting arm S9, so that the position of slide Se, and thereby of meter 8d can be pre-set. The desired thickness of a split layer c is set by operating handle 85 until pointer 49 indicates the respective thickness c. Y

Referring now to PEG. 3, which illustrates the electric circuit used in the embodiment of FIG. 1, the eld Windings of motor i3 are connected to a pair of switches 57 and 59 by which the motor can be reversed, or disconnected. Switches 57 and 5% are operated by electromagnetic means S and 53. A transformer 73 has a primary winding connected to a source of voltage, and a secondary winding connected at one end to the coils of electromagnetic means 56 and 53. The other end of the secondary winding of transformer 7d is connected to the control switch 7, and to a manually operated switch which can be shifted between positions in contact with stationary contacts 9i? or 9i. When the manually operated switch 95 is connected to contact 99, electromagnetic means Se is energized, and effects through switch 57 turning of motor 13 in one direction, whereas switch 95 in contact with contact 9i will eect energization of electromagnetic means 58, actuation of switch 59, and running of motor 13 in the opposite direction.

The manually operate-d switch 95 is usedfor presetting support 14 with pressure roller 2 in accord-ance with the indication on a scale 92 by pointer 93.

As explained above, the meter 84 has a movable c011- tact 61 cooperating with two terminal contacts 11 and 12. Movable contact 61 is connected in series with a delay switch 89 controlled yby la delay relay 79, 8. Delay switch 80 is connected in series with control switch 7, while the coil 7 9 connects control switch 7 with the secondary winding of transformer 7 S.

When a sheet material -is inserted between the rollers 2 :and 3, counter-pressure roller 3 is displaced, land closes control switch 7. A current ilows through winding 79, so .that delay switch Sil closes after a delay corresponding to the time required for the split olf layer of the workpiece to reach the feeler roller 6.

As long as there is no workpiece between the rollers `V 2 and 3, the feeler roller 6 is urged by a spring 55 toward roller 2., corresponding to a workpiece which is too thin, and consequently movable contact 61 abuts the stationary contact 12. However, since control switch 7 is open yas long as there is no workpiece between the rollers 2 and 3, no current can now through coil 58. As explained above,

61, 12, switches 7, 89, and electromagnetic means 58 by which switch S9 is closed to edect rotation of motor 13, and adjustment of the position of pressure roller 2. Such adjustment takes place, if the split layer is too thin. However, if the split layer is too thick, sensing finger 86 will be displaced by `feelerlever 83, 8d, and the movable contact 61 will engage the stationary contact 11, and effect through electromagnetic means 55 closing of switch 57 and turning of motor 13 in the opposite direction. If the split layer has -a desired thickness c located -within the range determined by the stationary contacts 11 and 12, movable contact 51 will assume an intermediate position in which no current will ow through any of the electromagnetic means Se or S3, so that switches 57 `and 59 will vassume the position shown in FIG. 3 in which the motor 13 is ata standstill.

Since the -compressibility of the workpiece cannot be exactly predicted, the preliminary setting may be wrong so that the movable contact 61 may Eat first engage either contact .11, or contact 12. However, in this event, motor 13 will be energized to adjust the position of the pressure roller 2 until the split layer has the desired thickness c. The variation of the thickness c is due to the fact that the pressure roller 2 presses workpiece 1 and counterpressure roller 3 downwardly until the workpiece 1 assumes la position relative to the cutting edge 4 in which a layer of the desired thickness c is split olf the sheet material of the workpiece. When the end of the workpiece passes between the two rollers 2 and 3, the control switch 7 opens and switch dii also opens after a delay so that no undesired adjustment `can take place when feeler roller 6 moves toward pressure roller 2 after the end of the split layer 'has passed out of the gap between rollers' 2 and 6. A curved guide 81 is advantageously provided for guiding the split layer onto conveyor 41.

From the above description of a preferred embodiment of the invention, it -will become apparent that the split-oil? layer is sensed by feeler means in its normal expanded condition so that the actual desired thickness of the layer determines the adjustment of the splitting apparatus.

1y rdeviation `from the desired thickness, within a narrow range of tolerances deter-mined `by the adjustable contacts 11 Iand 12, is used for obtaining the necessary adjustment of the apparatus. lt is important that the split-off layer -is transported at the same speed as the sheet material gripped by the transporting rollers, since otherwise the material would be gathered and accumulate between the feeler roller 6 and the transporting rollers. Consequently, a transporting roller driven in synchronism with transporting roller 2 may be provided opposite eeler roller 6', but in the preferred embodiment of the invention, feeler roller 6 lis located directly opposite the transporting and pressure roller 2. i*

A plane passing through the axis of roller 2 and the cutting edge 4 denes the line S on the peripheral surf-ace of roller 2. Another plane through the taxis of roller 2 Vand through the -axis of roller 6 defines -a line M on the peripheral surface of roller 2. The angular distance Ebetween points S yand M is the arc f which is shown in the diagrammatic view of FIG. 2. The sheet material has a normal thickness a, and the split layer has a thickness c. The range `of tolerance is T, and is indicated by the two outer chain lines `in FIG. 2. Any thickness between these outer lines is acceptable, but the desired accurate thickness c is represented by the inner chain line which is spaced distances T/ 2 lfromI the outer chain lines.

The control speed Vr at which the pre-saure roller 2 is moved by the motor 13 is selected to lbe in a predetermined ratio with t-he transporting and :feeding speed Vv of the sheet material determined by the peripheral speed of pressure roller 2. The ratio must be selected in such a manner that when Contact 61 separates from one of contacts 11 or i12 due to the -fact that feeler roller 6 senses a thickness of the layer within the tolerance range, Iand ,motor 13 consequently stops, the desired thickness c is y the desired thickness of the split layer can be set.

exactly obtained due to the fact that the material travels the distance f between the cutting edge d ,and the feeler roller 6.

From this follows:

Since the distance f, as well as the range of tolerances T is predetermined, and since the transporting and feeding `speed Vv is given by the machine, the control speed V r can be determined from the above equation without any diticulty. The ratio betweeen the control speed and the feeding speed is kept constant so that intended or necessary vari-ations of the feeding speed, for example when very `hard workpieces are spl-it, have no influence on the exactness of the adjustment to the desired thickness.

At the beginning ot a splitting operation, the desired hickness of the usable layer is roughly pre-set by operation of the manually operated switch whose shifting wdl effect rotation of motor 13 in opposite directions, and corresponding movement of pressure roller toward and away from the counter-pressure roller 3 so that the position of the pressure roller 2 is indicated by pointer )3 on scale h2.. This scale does not necessarily indicate the thicknesses c, but can also be related to the compressibility 'of the sheet material. For example, batches or animal skins may be assorted in accordance with their diderent compressibility, and in this event separate scales can be provided for setting the machine in accordance with the indicated percentages of the ratio of compressibility between the thickness a and the thickness e. Scales and tables can also be devised in which, for each previously determined percentage ratio of eompressibility, It is only necessary to set the same desired thickness, for example inmilimeter, on the scale 48 by which the position of the meter Sd is determined.

By suitable selection of the length of the arms S3 and S3 of the sensing lever 83, and by properly positioning the ulcrurn of the sensing lever 83, 8, distortions affecting the cooperation between the feeler roller 6, and the operation of the meter finger S7, can be held within negligible limits.

The delay relay 79, d is designed in such a manner that delay switch t) closes after the time required for the workpiece to move through the arc f from the cutting line S to the sensing line M, in other words the meter becomes eiective only when the workpiece is being sensed by the feeler roller d.

-lt is advantageous to construct the counter-pressure roller 3 of a plurality of independently movable axial roller sections, each of which is mounted on a supporting arm 2e. ln this manner, the pressure of pressure roller@ does not produce a greater speciiic pressure on narrower workpieces than ony wider workpieces, which may result in an undesired Variation of the thickness of the finished product due to the different compression of narrow and wide workpieces. l the counter-pressure roller is constructed of several axial roller sections, only those sections which support a workpiece,A will be displaced, moving with the correlated armsV 26 against the pressure of the respective correlated springs 29.

lt is preferred to provide adjusting means for spring 55 so that the pressure of the feeler roller on the workpiece can be adjusted in accordanceV with the compressibility and resiliency of the workpiece.

As explained above, the machine automatically adjusts itself while the first workpiece is run through the machine. However, this requires a certain length of the first workpiece, and when the first workpiece is too short, it is advisable to run the same two or three times through the machine until the machine is accurately set 7 machine will automatically adiust itself to the desired thickness, and will again carry out an automatic adjustment when for any reason whatsoever, for example varying properties of the material such as variations of the hardness md resiliency, the obtained thickness falls outside of the range of tolerances.

it will be understood that each of the elements described above, or two or more together, may also find a useful application in other types of splitting machines for splitting sheet material, such as animal skins, differing from the types described above.

While the invention has been illustrated and described as embodied in a control arrangement for automatically adiusting a splitting machine in accordance with the thickness of the split-oil layer, it is not intended to be limited to the details shown, since various modifications and structural changes may be made without departing in any way from the spirit of the present invention.

Without further analysis, the foregoing will so fully reveal the gist of the present invention that others can by applying current knowledge readily adapt it for various applications without omitting features that, from the standpoint of prior art, fairly constitute essential characteristics of the generic or specific aspects Vof this invention and, therefore, such adaptations should and are intended Vto be comprchended within the meaning and range of equivalence of the following claims.

What is claimed as new and desired to be secured by Letters Patent is:

l. A splitting machine comprising, in combination, a cutting means; transporting means for transporting a sheet material in one direction toward said cutting means and for pressing the'sheet material against the same so that the sheet material lis compressed and split into two layers which resiliently expand behind said cutting means; and a control device including a feeler located behind said cutting means in said direction for directly sensing the thickness of one of said expanded layers, said control device being operatively connected to one of said means to adjust the position thereof relative to the other of said means until said feeler senses a desired thickness of said one layer whereby a layer of the desired thicknessk is obtained irrespective of the thickness, compressibility and actual compression of the sheet material.

2. A splitting machine comprising, in combination, a`

cutting means; transporting means for transporting a sheet material in one direction toward said cutting means and for pressing the sheet material against the same so that the sheet material is compressed and split into two layers which resiliently expand behind said cutting means; and a control device including a Vfeeler located behind said cutting means in said direction for engaging one of said expanded layers and for directly sensing the thickness thereof, said control device being operatively connected to said transporting means to adjust the position thereof relative to said cutting means until said feeler senses a desired thickness of said one layer whereby a layer of the desired thickness is obtained irrespective of the thickness, compressibility and actual compression of the sheet material.

3. A splitting machine comprising, in combination, a cutting means located in `a working plane; transporting means including a first yroller and ya second roller for transporting a sheet material in said worlcng plane in one direction toward said cutting means and for |pressing the sheet material against the same, said iirst roller being movable `toward said second roller and toward said cutting Imeans in a transverse direction so that the sheet material is compressed and split into two layers which resiliently expand behind said cutting means; and -a conv trol device including a feeler located behind said cutting means in said one direction Iand opposite one of said rollers for engaging one of said expanded layers and for directly'sensing the thickness thereof, said control device being operatively connected to said first vroller'to adjust bfi Cil

the position thereof relative to said second roller until said feeler senses a desired thickness of said one layer whereby a layer of the desired thickness is obtained irrespective of the thickness, compressi-bility and vactual compression of the sheet material. i i

4. A splitting machine comprising, in combination, a

cutting'means; transporting means including a counterbehind said cutting means in said direction and opposite said pressure roller for sensing the thick-ness of .the one of said expanded layers which passesv between said pressure roller andsaid feeler means; and operating means connected to said support and being controlled by said feeler means to move said pressure roller toward and away from said counter-pressure means fand said cutting means until said feeler means senses a desired thickness of said one layer whereby a layer of the desired thickness is obtained irrespective o-f the thickness, compressibility and actual compression of -the sheet material. Y

5. A splitting mach-ine comprising, in combination, a cutting means; transporting means including a counter'- pressure means, a .pressure roller, anda support turnablyV supporting said pressure roller and being movable with the same toward and away from said counter-pressure means, said roller being driven to transpont a sheet material in one direction toward said cutting means, and to press the sheet material against the same so `that the sheet material is compressed and split into two layers which resiliently expand behind said cutting means; a feeler mean-s turnably mounted on said support and 4having a feeler portion l0- cated behind said cutting means in said direction and opposite said pressure roller for sensing the thickness of the one 'of said expanded layers which ypasses between said pressure roller and said feeler means; and operating means connected to said support and being controlled by said feeler means to move said pressure roller toward and away from said counter-pressure means and said cutting means until said feeler means lsenses la desired thickness of said one layer whereby a layer of the desired thickness.y i

` is obtained irrespective 'of the thickness, compress-ibility and actual compression of the sheet material.

`6. A splitting machine comprising, in combination, a

cutting means; transporting means including a counterpressure means, a pressure roller, 4and a support -turnably supporting said pressure roller and being movable with the same toward and away from said counter-pressure,

means, said roller being driven to transport a sheet material in one direction toward said cutting means, and to press the sheet material against ,the same so that the sheetY material is compressed yand split into two layers which resiliently expand behind said cutting means; a feeler means turnably mounted on saidl support and including a turnable feeler roller located behind said cutting means in said Y direction and opposite said pressure roller for sensing thev thickness of rthe one of said expanded layers which passes between said pressure roller and said feeler means, said Y feeler means including resilient means for urging said feeler roller toward said pressure roller and against said one' layer; fand operating means connected to said support and being controlled by said Vfeeler means to move said pressure roller toward and away `from said counter-pressure means and said cutting Irneans'until said feeler means senses a desired thickness of said one layer whereby a layer ofthe desired thickness is obtained irrespective of the thickness,Y

compress-ibility and actual compression of ythe sheet material.

7. A splitting machine comprising, in combination, a

cutting machine; transporting means including :a counter- 9 pressure means, a pressure roller, and a support turnably supporting said pressure roller and being movable with the same toward and away lfrom -said counter-pressure means, said roller being driven at a selected speed to transport a sheet material at a selected feeding speed in one direction toward said cutting means, and to press the sheet material against the same so that the sheet material is compressed and split into ltwo layers which resi-liently expand behind 'said cutting means; a ffeeler means located behind said cutting means in said direction and opposite said pressure roller for sensing the thickness of the one of said expanded layers which `passes between said pressure roller and said feeler means; and operating means connected to said support and being controlled by said `feeler means to move said pressure roller toward and away from said counter-pressure means and said cutting means at a selected control speed until said feeler -means senses a desired thickness of said one layer whereby a layer of desired thickness is obtained irrespective of the thickness, compressibility yand actual compression of the sheet material, said feeding speed 'and said control speed having such la ratio that during :the movement of any portion of said one layer from said cutting means to said feeler, said pressure roller moves a distance substantially equal to half of the total tolerance between the maximum and values of said desired thickness.

8. A splitting machine comprising, in combination, a cutting means; 4transporting means for transporting a sheet material at a selected feeding speed in one direction toward said cutting means and for pressing the sheet material against the same so that the sheet material is compressed and split into two layers which resiliently expand behind said cutting means; and a control device including a feeler located behind said cutting means in said direction for engaging one of said expanded llayers and for directly sensing the thickness thereof, said control device being operatively connected to one of said means to adjust the position thereof relative to the other of said means at a selected control speed until said feeler senses a desired thickness of said one llayer whereby a layer of the desired thickness :is obtained irrespective of the thickness, compressibility and actual compression of the sheet material, said feeding speed 'and said control speed having such a ratio that during -the movement of Aany portion of said one layer from said cutting means to said feeler, said pressure roller moves a distance substantially equal to half of the total tolerance between the maximum and minimum v-alues of -said desired thickness.

9. A splitting machine comprising, in combination, a cutting means; transporting means including a counterpressure means, a pressure roller, and a support turnably supporting said pressure roller and being movable with the same toward and away from said counter-pressure means, said roller bein-g driven to transport a sheet material in one direction toward said cutting means, and to press the sheet material against the same so that the sheet material is compressed and split into two layers which resiliently expand behind said cutting means; a feeler means located behind said cutting means in said direction and opposite said pressure roller for sensing the thickness-of the one of said expanded layers which passes between said pressure roller and said -feeler means; and operating means including a motor, transmission means driven by said motor and connected to said support, a control circuit connected to said motor and including switch means for effecting turning of said motor in opposite directions and stopping of said motor, said switch means being operatively connected to said feeler means and controlled by the same to eect movement of said pressure roller toward and away from said counter-pressure means and said cutting means until said fceler means senses -a desired thickness of said one layer whereby a layer of the desired thickness is obtained irrespective of the thickness, compressibility and actual compression of the sheet material.

l0. A splitting machine comprising, in combination, a

10 cutting means; transporting means including ya counterpressure means; a pressure roller, and a support turnably supportin-g said pressure roller and being ymovable with the same toward and away from `said counter-pressure means, said roller being driven to transport a sheet material in .one direction toward said cutting means, and to press' the sheet material against the same so that the sheet material is compressed and split into two layers which resiliently expand behind said cutting means; a feeler means located behind said cutting means in said direction and opposite said pressure roller for sensing the thickness of the one of said expanded layers which passes between said pressure roller and said feeler means; and operating means including a motor, transmission means driven by said motor and connected to said support, a control circuit connected to said motor and including switch means for effecting Iturning of said motor in opposite directions and stopping of said motor, and a meter mounted on said support for measuring the displacement of said feeler means, said meter includ-ing a movable contact and two fixed contacts on opposite sides of said movable contact, said control circuit including electromagnetic means for operating said switch lmeans, and said contacts being con- Y nected to said electromagnetic means for energizing the same to eiect operation of said switch means so that the same are controlled to effect movement of said pressure roller toward and away from said counter-pressure means and said cutting means until said feeler means senses a desired thickness of said one layer whereby `a layer of the desired thickness is obtained irrespective of the thickness, compressibility and actual compression of the sheet material.

11. A machine as set forth in clairn 10i wherein said circuit includes manually operated switch means for effecting energizing of said electromagnetic means whereby said pressure roller can be set to a selected position.

12. A machine =as set forth in claim ll including an indicating means on said support, and a cooperating stationary indicating means whereby the distance between said pressure means, and said counter-pressure roller and cutting means can be pre-set.

13. A machine as set forth in claim l0 and including a slide mounted on said support for movement in the direction in which said support moves; and manually operated adjusting means on said support connected to said slide for moving the same, said slide supporting said meter.

14. A machine as `set forth in claim 13 wherein said feeler means includes a lever pivotally mounted on said support, and a feeler roll turnably mounted on said lever and located opposite -said pressure roller for sensing said one layer; and spring means intermediate said lever and said support for urging said feeler roller against said one layer.

-15. A machine as set forth in claim 13 wherein said adjusting means includes a micrometer screw; including indicating means on said support for indicating the position of said slide; and stop means for stopping said slide in two end positions.

16. A splitting machine comprising, in combination, a cutting means located in a working plane; transporting means including a resiliently supported counter-pressure means, a pressure roller, and a support turnably supporting said pressure roller and being movable with the same toward and away from said counter-pressure means, said roller being `driven to transport a sheet material in one direction toward said cutting means, and to press the sheet 4 material against the same so that the sheet material is compresesd and split into two layers which resiliently expand behind said cutting Ine-ans; stop means for stopping said counter-pressure means when its extremity is located in said working plane; a feeler means located behind said cutting means in said direction and opposite said pressure roller for sensing the thickness of the one of said expanded layers which passes between said pressure roller and said feeler means; and operating means including a motor, transmission means driven by said motor and connected to said support, a control circuit connected to said motor and including a normally open control switch locat-ed to be closed by said counter-pressure means when the same is displaced out of said working plane by the sheet material under pressure of said pressure roller, switch means for effecting turning oi said motor in opposite directions and stopping of said motor, and a meter mounted on said support for measuring the displacement of said feeler means, said meter including a movable contact and two fixed contacts on opposite sides of said movable contact, said control circuit including electromagnetic means for operating said switch means, and said contacts being connected to said electromagnetic means for energizing the same to effect operation of said switch means so that the same are controlled to effect movement of said pressure roller toward and away from said counter-pressure means and said cutting means until said feeler means senses a desired thickness of said one layer whereby a layer of the desired thickness is obtained irrespective of the thickness, compressibility Vand actual compression of the sheet material.

17. A machine as set forth in claim 16 wherein said control circuit include-s delay means connected to said control switch so that the movable contact in the meter can energize the electromagnetic means only after a delay when a sheet material placed between said pressure roller and said counter-pressure means is located between said pressure roller and said feeler means.

18. A machine as 'set forth in claim 17 wherein said del-ay means includes a delay switch connected in series with said movable Contact and said control switch, and an electromagnet connected in series with said control switch and with one pole of a transformer; said feeler means including a feeler portion adapted to engage said one layer and a movable arm cooperating with said meter; the arrangement being `such that said motor is only energized to adjust the position of said pressure roller when said one layer is transported to a position located between said pressure roller and said feeler portion before opening said control switch.

19. A machine as set forth in claim 16 wherein said resiliently supported counter-pressure means includes a movable support, a counter-pressure roller turnably mounted on said support and located opposite said pressure roller, a spring-loaded shift-able member abutting Said movable support for urging said counter-pressure roller toward said pressure, roller, and a stop for stopping movement of said shiftable member in a position in which the peripheral surface of said counter-pressure roller is located in said working plane; and wherein said control switch is operated by said shiftable member.

20. A splitting machine comprising, in combination, Va cutting means located in a working plane; tnansporting means including a resiliently supported counter-pressure roller, a pressure roller, and a support turnably supporting said pressure roller and being movable with the same toward and away from said counter-pressure roller, said pressure roller being driven to transport a sheet material in one direction toward said cutting means, and to press the sheet material against the same so that the sheet material is compressed and split into two layers which resiliently expand behind said cutting means; stop means for stopping said rcounter-pressure roller when its periph-V eral surface is located in said working plane of said cntting means; Ia normally open control switch located to be closed when said counter-pressure roller is displaced by sheet material located between said rollers; a feeler means located behind said cutting means in said direction and opposite said pressure roller for sensing the thickness of the one of said expanded layers which pasess between said pressure roller and said feeler means; and operating means including a motor, transmission means driven by said motor and connected to said support, a controloircuit connected to said motor and to said control switch so that said motor is disconnected when said control switch is open, said control circuit yincluding switch means for eecting turning of said motor in'opposite directions and stopping of said motor, said switch means being operatively connected to said feeler means and controlled by the same to effect movement of said pressure roller toward :and away from said counter-pressure roller and said cutting means until said feeler means senses a desired thickness of said one layer whereby a layer of the desired thickness is obtained irrespective of the thickness, compressibility and actual compression of the sheet material.

References Cited in the file of this patent UNITED STATES PATENTS 

1. A SPLITTING MACHINE COMPRISING, IN COMBINATION, A CUTTING MEANS; TRANSPORTING MEANS FOR TRANSPORTING A SHEET MATERIAL IN ONE DIRECTION TOWARD SAID CUTTING MEANS AND FOR PRESSING THE SHEET MATERIAL AGAINST THE SAME SO THAT THE SHEET MATERIAL IS COMPRESSED AND SPLIT INTO TWO LAYERS WHICH RESILIENTLY EXPAND BEHIND SAID CUTTING MEANS; AND A CONTROL DEVICE INCLUDING A FEELER LOCATED BEHIND SAID CUTTING MEANS IN SAID DIRECTION FOR DIRECTLY SENSING THE THICKNESS OF ONE OF SAID EXPANDED LAYERS, SAID CONTROL DEVICE BEING OPERATIVELY CONNECTED TO ONE OF SAID MEANS TO ADJUST THE POSITION THEREOF RELATIVE TO THE OTHER OF SAID MEANS UNTIL SAID FEELER SENSES A DESIRED THICKNESS OF SAID ONE LAYER WHEREBY A LAYER OF THE DESIRED THICKNESS IS OBTAINED IRRESPECTIVE OF THE THICKNESS, COMPRESSIBILITY AND ACTUAL COMPRESSION OF THE SHEET MATERIAL. 